At present, a known blistering machine M for producing blister packs, according to FIG. 1 (prior art) includes: a station 1, in which a first continuous band 2 of thermoformable material (e.g. PVC) is thermoformed to define a blister band with blisters 3 containing products 4, the blister band 2 being driven continuously along a determined feeding path A having a varying course; a station 5 for feeding products 4, including a unit for filling each blister 3 with a product 4; a station 6 for driving a second continuous band 7 (e.g. of aluminium), feeding continuously the second continuous band 7 over the blister band 2 filled with the products 4; a station 8 for closing the first blister band 2 with the second band 7 by heat-sealing, in order to obtain a continuous blister pack band NB.
Downstream of the closing station 8, along the feeding path A of varying course, there is also a station 9, where the continuous blister pack band NB is printed or punched, and a station 10, where the continuous blister band NB is pre-cut, to define pre-cut lines on the continuous blister pack band NB.
Afterwards, the continuous blister pack band NB with the pre-cut lines is divided, e.g. by shearing at a cutting station R, to define a plurality of single blister packs B.
Downstream of the cutting station R, the single blister packs B are collected and fed to a boxing +unit C, to be packaged in suitable boxes in known way.
Generally, the printing station 9, as well as the pre-cutting station 10 include a pair of opposed plates working alternately to move toward and away from the blister band NB.
Since the first band 2, as well as the second band 7, and consequently, the band NB, are fed continuously, it is necessary to make this continuous feeding of the band NB compatible with the alternate motion of the means in the printing station 9 and the pre-cutting station 10.
For this purpose, the machine M includes a bending roller 11, which bends the band NB downstream of the closing station 8 and makes it move along an acute angle curved portion of the feeding path A defining a loop K.
The idler roller 11, defining the loop K, is a so-called “dancing” roller, that is a roller, which is made oscillate between different working positions, in order to allow to make up for the continuous feeding of the band NB along the path A.
Although the above described configuration bending roller 11—loop K is efficient in making the continuous movement of the band NB compatible with the alternate movements of the stations 9 and 10, it constitutes a limit to the possibility of increasing the productive speed of the blistering machine M.
Moreover, this configuration increases the dimensions of the blistering machine M.